major connectors in rpd

7/25/2019 Major Connectors IN RPD

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Major ConnectorsMajor Connectors


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Functions of a Major ConnectorFunctions of a Major Connector

Unification

Partial denture acts as one unit

Connects various parts

Unification

Partial denture acts as one unit

Connects various parts


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Stress Distribution

Distributes functional loads to both

teeth & mucosa

Stress Distribution

Distributes functional loads to both

teeth & mucosa


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Cross-Arch Stabilization

(Counterleverage)

Bracing elements on one side of thearch providing stability to the other

Cross-Arch Stabilization

(Counterleverage)

Bracing elements on one side of thearch providing stability to the other


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Requirements of a Major ConnectorRequirements of a Major Connector

Rigidity

Functions as one unit

Rigidity

Functions as one unit


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To Increase RigidityTo Increase Rigidity

Use a more rigid alloy

Chrome-cobalt > gold alloys; cast > wrought

Shape

1/2 round > 1/2 pear shaped > flat bars

Use a more rigid alloy

Chrome-cobalt > gold alloys; cast > wrought

Shape

1/2 round > 1/2 pear shaped > flat bars


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To Increase RigidityTo Increase Rigidity

Increase the bulk as the length increases

Corrugate linguo-plate or rugae areas

Increase the bulk as the length increases

Corrugate linguo-plate or rugae areas


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RequirementsRequirements

Non-Interference with Tissues

Should not enter undercut areas

avoid by changing path of insertion

or by using blockout

Non-Interference with Tissues

Should not enter undercut areas

avoid by changing path of insertion

or by using blockout


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Non-Interference With TissuesNon-Interference With Tissues

Avoid terminating on:

Free gingival margin

Cross abruptly at 90o

Relief is used to minimize

impingement


Free gingival margin

Cross abruptly at 90o

Relief is used to minimize

impingement

(Fig 2-17, Stewart's)


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Hard structures such as the mid-

palatal suture or mandibular tori

Place relief


Hard structures such as the mid-

palatal suture or mandibular tori

Place relief


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Lingual frenum & the movable soft palate

Soft tissue movements must also be allowed

Careful intraoral exam

Avoid terminating on: Lingual frenum & the movable soft palate

Soft tissue movements must also be allowed

Careful intraoral exam


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Minimize Food ImpactionMinimize Food Impaction

Locate margins away from the FGM

Eliminate "traps" or large concavities

where food can collect

Locate margins away from the FGM

Eliminate "traps" or large concavities

where food can collect


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UnobtrusiveUnobtrusive

Smooth transition from connector to

denture base - butt joint

Smooth transition from connector to

denture base - butt joint


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UnobtrusiveUnobtrusive

Line angles and edges should be smooth

and rounded

Borders should not interfere with speech

Line angles and edges should be smooth

and rounded

Borders should not interfere with speech



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Mandibular Major ConnectorsMandibular Major Connectors

Lingual Bar

Lingual Plate

Continuous Bar

Lingual Bar

Lingual Plate

Continuous Bar


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Lingual Bar

Most common in mandibe

Use whenever possible

Lingual Bar

Most common in mandibe

Use whenever possible


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Lingual Bar

Shape

Flat on tissue side

Convex or tear-drop on

tongue side

(1/2 pear shape, with

thin edge toward teeth)

Lingual Bar

Shape

Flat on tissue side

Convex or tear-drop on

tongue side

(1/2 pear shape, with

thin edge toward teeth)



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Lingual Bar

Size

Occluso-gingival width = 4 to 6 mm

Thickness = l.5 to 2 mm

Lingual Bar

Size

Occluso-gingival width = 4 to 6 mm

Thickness = l.5 to 2 mm


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Inferior Border MandibleInferior Border Mandible

Patient lifts tongue

Activates floor of mouth

Measure from tip of probe to free

gingival margin

Patient lifts tongueActivates floor of mouth

Measure from tip of probe to free

gingival margin


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Inferior Border MandibleInferior Border Mandible

Record values in chart, transfer to cast Record values in chart, transfer to cast


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Lingual BarLingual Bar Position

Superior border

l.5-2.0 mm or more below FGM

As far from gingival margin as

possible

PositionSuperior border

l.5-2.0 mm or more below FGM

As far from gingival margin aspossible



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Potential ImpingementPotential Impingement

Anterior major connector moves toward tissueas the posterior portion is loaded

Space needed more when ridge is less vertical

Anterior major connector moves toward tissueas the posterior portion is loaded

Space needed more when ridge is less vertical



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Mandibular Major Connector ReliefMandibular Major Connector Relief

Eliminates impingement

Wax spacer (relief) placed under major

connector

one thickness of 30 gauge wax

Eliminates impingement Wax spacer (relief) placed under major

connector

one thickness of 30 gauge wax


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Lingual Plate (Linguoplate)Lingual Plate (Linguoplate)

Lingual bar with extension over cingula ofanterior teeth

Use where a lingual bar cannot be used

Lingual bar with extension over cingula ofanterior teeth

Use where a lingual bar cannot be used


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Lingual Plate IndicationsLingual Plate Indications

Potential Impingement from lingual bar

High floor of the mouthProminent lingual frenum

Lingual tori

Potential Impingement from lingual bar

High floor of the mouth

Prominent lingual frenum

Lingual tori


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Lingual PlateLingual Plate

Rest at each end of lingual plate

Prevents forces being directed facially

Easier denture tooth addition than bar

Rest at each end of lingual plate

Prevents forces being directed facially

Easier denture tooth addition than bar


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Lingual Plate VariationsLingual Plate Variations

May show through embrasures May show through embrasures

(Fig 2-41 & 43, Stewart's)


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Continuous Bar Retainer(Kennedy Bar, Double Lingual Bar)

Continuous Bar Retainer(Kennedy Bar, Double Lingual Bar)

Lingual bar with secondary bar above

cingula

Secondary bar acts as indirect retainer

Lingual bar with secondary bar above

cingula

Secondary bar acts as indirect retainer


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Continuous Bar RetainerContinuous Bar Retainer

Potential food trap between two bars

Normally avoid

Potential food trap between two bars

Normally avoid


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Maxillary Major ConnectorsMaxillary Major Connectors

Anterior-Posterior Palatal Strap

Full Palatal Strap

Palatal Strap

Anterior Palatal Strap

Anterior-Posterior Palatal Strap

Full Palatal Strap

Palatal Strap

Anterior Palatal Strap


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Maxillary Major ConnectorsMaxillary Major Connectors

Terminate 4.0 mm or more from free

gingival margin when possible

Terminate 4.0 mm or more from free

gingival margin when possible


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Anterior-Posterior Palatal StrapAnterior-Posterior Palatal Strap

Maximum rigidity

Minimum bulk

Use in most cases

Especially torus palatinus

Maximum rigidity Minimum bulk

Use in most cases

Especially torus palatinus


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Anterior-Posterior Palatal BarAnterior-Posterior Palatal Bar

A narrow (A-P) variation of anterior-posterior palatal strap

Double palatal bar connector

Requires greater bulk for rigidity

A narrow (A-P) variation of anterior-

posterior palatal strap

Double palatal bar connector

Requires greater bulk for rigidity


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Anterior-Posterior Palatal BarAnterior-Posterior Palatal Bar

More objectionable to the patient

Strap connectors provide greater

distribution of stresses

More objectionable to the patient

Strap connectors provide greater

distribution of stresses


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Full Palatal PlateFull Palatal Plate

Maximum tissue support

Connector of choice in long distal

extension cases

Six or less anterior teeth remain

Maximum tissue support

Connector of choice in long distal

extension cases

Six or less anterior teeth remain


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Abutments are periodontally involved

Maximum stress distribution

Flabby tissue

Shallow palatal vault

Abutments are periodontally involved

Maximum stress distribution

Flabby tissue

Shallow palatal vault


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Greater stability and stress distribution

Not used with torus

Increases retention

Greater stability and stress distribution

Not used with torus

Increases retention


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Connector should:

Be fabricated of uniformly thin metal

Have accurate anatomic reproduction

of the ruggae

improves strength and rigidity

Connector should:

Be fabricated of uniformly thin metal

Have accurate anatomic reproduction

of the ruggae

improves strength and rigidity


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Connector should: Cover same area as complete denture

posteriorly

Have large surface area of mucosal contact

improves potential for retention

Connector should:

Cover same area as complete denture

posteriorly

Have large surface area of mucosal contact

improves potential for retention


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Generally of cast metal

Acrylic resin used in interim prostheses

Generally of cast metal

Acrylic resin used in interim prostheses


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Palatal StrapPalatal Strap

Usually use for Class III & IV cases

Wide anterio-posteriorly

Usually use for Class III & IV cases

Wide anterio-posteriorly


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Palatal BarPalatal Bar

Dont use

Narrow anterio-posteriorly

Thick occluso-gingivally

Palatal bar objectionable due to bulk

Dont use

Narrow anterio-posteriorly

Thick occluso-gingivally

Palatal bar objectionable due to bulk



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Palatal Strap (or Bar)Palatal Strap (or Bar)

Never use in cases involving distal extensions orreplacement of anterior teeth since it must be

made bulky for rigidity

Relief may be required over bony midline

Not used with torus

Neveruse in cases involving distal extensions orreplacement of anterior teeth since it must be

made bulky for rigidity

Relief may be required over bony midline

Not used with torus


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Anterior Palatal Plate(U-Shaped or "Horse-Shoe" Palatal Connector)

Anterior Palatal Plate(U-Shaped or "Horse-Shoe" Palatal Connector)

Poor connector

Never use unlessabsolutely necessary

Requires bulk in the

rugae area (wherethe tongue requires

freedom) for rigidity

Poor connector

Neveruse unlessabsolutely necessary

Requires bulk in the

rugae area (where

the tongue requires

freedom) for rigidity


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Anterior Palatal PlateAnterior Palatal Plate

Too flexible

Allows movement at the posterior Traumatic to the residual ridge

Use only where torus prohibits other

connectors

Too flexible

Allows movement at the posterior Traumatic to the residual ridge

Use only where torus prohibits other

connectors


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Flexes, impinging on soft tissue


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Unilateral RPDUnilateral RPD

Dangerous

Avoidaspiration

Dangerous

Avoidaspiration

major connectors in rpd

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